NEW YORK - The circumstances surrounding Harry Houdini's sudden death were as murky as the rivers where he often performed death-defying stunts. Despite a medical explanation, rumors that the escape artist was murdered have persisted for decades.

Eighty-one years after Houdini died on Halloween 1926, his great-nephew wants to exhume the magician's body to determine if enemies poisoned him for debunking their bogus claims of contact with the dead.

"His death shocked the entire nation, if not the world. Now, maybe it's time to take a second look," George Hardeen said.

Houdini's family scheduled a news conference for Friday to give details on the plans. Hardeen said a team of top forensic investigators would conduct new tests on Houdini's body.

The generally accepted version of Houdini's death held that the 52-year-old suffered a ruptured appendix from a punch in the stomach, leading to peritonitis. But no autopsy was performed.

When the death certificate was filed on Nov. 20, 1926, Houdini's body — brought by train from Detroit to New York — had already been buried, along with any evidence of a possible death plot.

Within days, a newspaper headline wondered, "Was Houdini Murdered?"

A 2006 biography, "The Secret Life of Houdini," raised the issue again and convinced some that he might have been poisoned, including Hardeen, who lives in Arizona and is the chief spokesman for the president of the Navajo Nation.

The likeliest suspects were members of a group known as the Spiritualists. The magician devoted large portions of his stage show to exposing the group's fraudulent seances.

In the Houdini biography, authors William Kalush and Larry Sloman detail a November 1924 letter in which one of the movement's devotees, Sherlock Holmes author Arthur Conan Doyle, said Houdini would "get his just desserts very exactly meted out ... I think there is a general payday coming soon."

Two years later, Houdini, by all accounts a man in extraordinary physical shape, was dead.

Kalush and Sloman say that "the Spiritualist underworld's modus operandi in cases like this was often poisoning" — possibly arsenic, which could be detected decades later.

The authors also suggest Houdini might have been poisoned by "an experimental serum" injected by one of his doctors at Detroit's Grace Hospital.

Houdini took the Spiritualists' death threats seriously, but he traveled without security, often accompanied only by his wife, Bess.

"If someone were hell-bent on poisoning Houdini," the authors wrote, "it wouldn't have been very difficult."

The team working on the exhumation includes internationally known forensic pathologist Dr. Michael Baden and professor James Starrs, a forensic pathologist who has studied the disinterred remains of gunslinger Jesse James and "Boston Strangler" Albert DeSalvo.

Baden, who led panels reinvestigating the deaths of President John F. Kennedy and civil rights leader Martin Luther King Jr., pointed out a pair of oddities in Houdini's death certificate: It noted his appendix was on the left side, rather than the right, and he said the diagnosis of appendicitis caused by a punch was "very unusual."

Starrs said he was long familiar with the story of Houdini's death, and believed the fatal injury was the result of an accident until he read the Houdini biography.

"My eyebrows went up when I read this book," Starrs said. "I thought, `This is really startling, surprising and unsettling, and at bottom, suspicious in nature.'"

The exhumation plan received support from a surprising source: Anna Thurlow, the great-granddaughter of "medium" Margery, whose husband Dr. Le Roi Crandon was one of the Spiritualist movement's biggest proponents and one of Houdini's enemies.

During a 1924 "seance," Margery channeled a "spirit" named Walter who greeted Houdini with a threat: "I put a curse on you now that will follow you every day for the rest of your short life."

"With people that delusional, you have to question what they're capable of,'" Thurlow said. "If there's any circumstantial evidence that Houdini was poisoned, we have to explore that."